1
A=(1-2x)²
=1-4x-4x²
B=(6x+3)(6x-3)
=36x²-9 identité remarquable
2.
E=(3x+5)²-2(3x+5)
=9x²+30x+25-6x-10
=9x²+24x+15 => développement
E=(3x+5)²-2(3x+5)
=(3x+5)(3x+5-2)
=(3x+5)(3x+3)
=3(3x+5)(x+1) => factorisation
pour x=2/3 avec 9x²+24x+15
9(2/3)²+24(2/3)+15
=9*4/9+48/3+15
=36/9+16+15
=4+16+15
=34
